Internal combustion engines commonly include poppet valves to control the flow of intake and exhaust gases through the intake and exhaust ports, respectively. Poppet valve assemblies commonly include a poppet valve having a disc portion and a stem extending from the disc. The end of the stem may include one or more annular grooves. When the valves are assembled to a cylinder head of an internal combustion engine, the valve stem is inserted through a valve guide, and a valve spring is positioned around the valve stem. A valve spring cap is positioned on an outer end of the valve spring, and valve spring keys are positioned on the valve stem in engagement with the annular grooves. The valve spring is then allowed to expand, and the valve spring cap engages the valve spring keys, pushing the valve spring keys into engagement with the grooves. The valve spring keys and valve spring cap retain the valve spring in a compressed configuration.
With reference to FIGS. 7 and 8, a prior art poppet valve assembly 10 of the type used in internal combustion engines includes a valve 11 having a stem 12 and a valve disc portion 13. An end 14 of stem 12 includes a plurality of annular grooves 15. The valve assembly 10 further includes a helical coil spring 16, a valve spring cap 17, and a pair of valve stem keys 18. Outer surfaces 19 of valve stem keys 18 form a truncated cone that wedges tightly against the tapered sidewalls 20 of opening 21 of valve spring cap 17 when assembled with valve spring 16 in a compressed state acting against surface 22 of a cylinder head.
Various devices have been developed to assist in assembling poppet type valves for internal combustion engines. However, known tools and devices may suffer from various drawbacks.